What does it mean to obey when in a wedding vow a woman says she will love, honor and obey her husband?
And does the Church still use the word obey in a marriage vow?

Answer by Fr. John Echert on 10/30/2012:

The husband is head of the household, which is not only the patriarchal system of the past but the teaching of Saint Paul, who uses it as an analogy and sign on Earth of the headship of Christ over the Church. But the husband must love his wife, in exercising this headship, as Christ loves the Church and died for Her. While not in all forms of the vows, it is still valid Christian teaching and should be practiced. The spouses are equal but with different roles.